In the face of global climate change, generally attributed to the burning of fossil fuels, there is a large interest in renewable power sources, such as solar and wind energy. Global demand has driven the cost of photovoltaic (PV) panels consistently lower—a drop of over 70% in the decade since 2006. Lower costs, together with incentives such as the U.S. Solar Investment Tax Credit, have contributed to a sharp rise in the installation of both residential and commercial solar power facilities. The U.S. achieved one million solar installations in 2016, generating over 29 GW of electricity.
In electrical installations served by an electric utility, power enters the installation at a Service Entrance into a Main Service Panel. In U.S. residential installations, power entering the main service panel comprises two 120-volt anti-phase 60 Hz feeds designated L1 and L2 plus a common neutral, N. In commercial installations, a 3-phase service is often supplied, comprising L1, L2, L3, and N. In other places in the world, a single-phase residential system may comprise only one 240 volt 50 Hz feed L, plus N.
The most common method of exploiting solar energy has been the so-called “grid-tied” system, in which DC power from solar cells is converted to AC power and fed backwards through the electrical meter to offset consumption from the grid. Many states in the USA have passed regulations mandating that electrical utilities shall permit this so-called net-metering system in which the cost of power consumed from the grid at one time of day is offset by a credit received for power fed back to the grid at a different time. However, as the amount of installed solar power increases, the electric utilities are starting to experience difficulties in absorbing the total amount of back-fed power during the peak sun hours and as a result, the end is in sight of the economic benefit for consumers in being able to feed power back to the grid when they are not at home to use it otherwise.
U.S. Pat. No. 8,937,822 to one of the present co-inventors, describes an alternative to net metering for solar power, which instead facilitates self-consumption of own, solar-derived power. This system features automatic, circuit-by-circuit transfer switches to select, for each branch circuit, whether it receives solar power or grid power. This decision is based on, among other things, the total amount of solar power being received at any moment. In order to use solar power to directly power loads, energy storage (i.e., a storage battery) must be used to average out the difference between solar power instantaneously received and the varying consumption of the home or business. Thus, solar energy received when the homeowner is not at home to use it can be stored in the battery and released for use when the homeowner is home.
FIG. 1 illustrates the power distribution portion of the Smart Load Center (SLC) disclosed in the above-incorporated '822 patent. It may be seen that, in contrast to the two power busses that normally extend down the center of a conventional breaker panel, and into which the circuit breakers are connected, the SLC includes four power bus bars—two for solar power or other alternative energy source, and two for utility grid power or other primary energy source. Quadruple bus bar 3000 is sized to handle at least 60 amps on each solar input lug L1 and L2 (3001) and at least 60 amps on each utility power input lug L1 and L2 (3002). The panel of FIG. 1 is typically installed as a sub-panel and fed from the main service panel through a 60 A or 100 A, two-pole feeder breaker. The solar input may be derived from a solar DC-to-AC load inverter (not shown), which is already electronically current limited. Single Pole, Double Throw (SPDT) relays 3003 are used to select power to each pole of each breaker either from one of the solar power bus bars or from a utility power bus bar. On each side, the breakers alternate between using L1 and L2, so that a pair of adjacent slots may be used for a double pole (240 V) circuit, such as needed for a well pump or tumble dryer. Each relay is controlled by a SLC controller, which may for example comprise an appropriately programmed microprocessor (not shown in FIG. 1, but its functions are described in more detail in the '822 patent). Each circuit breaker 3004/3005 leads to a branch circuit (not shown) that is routed through the house, thus providing electrical power to one or more appliances. Typically, several outlets are connected in parallel in the branch circuit, and appliances and other electrical equipment may be plugged into the outlets.
The energy provisioning and load demand by the appliances can change over time, and a dynamic scheduling is required. Based on the energy demand in the house and on the energy available from the grid and the alternative power source like solar, appliances can be connected to grid or solar power. To make this system work, two communication functions must be fulfilled:                Identification of which appliance is connected to which branch circuit, and        Communication from the appliance to the Smart Load Center to reveal its need.        
In WO 2016123463 A2 and its Continuation-in-Part US 2016/0224083 A1 to one of the present co-inventors, a method has been described to use a low-rate Power Line Communication (PLC) system to provide the identification and communication elements. These documents are hereby incorporated by reference in their entireties. This low-rate PLC system makes use of inductively injecting information signals on a common mode of the Live and Neutral wires.
Another trend which has recently received a lot of attention is Home Automation. Home automation is part of a bigger trend called Internet-of-Things (IoT), which is a form of machine-to-machine (M2M) communication where any device can be connected to the Internet, either to provide (sensory) data or to be remotely controlled. For Home Automation, this means that appliances like the refrigerator, the washing machine, the electric stove, and also HVAC, are connected to the Internet and can be queried and controlled remotely via applications (apps) on a smartphone. For ease of use, the communications within the IoT ecosystem in general, and for Home Automation in particular, is wireless, based on standard and widely used protocols like WiFi and Bluetooth. Release 13 of the 3rd Generation Partnership Project (3GPP) defines three technologies to support M2M communications over cellular networks: Extended Coverage GSM Internet of Things (EC-GSM-IoT), LTE for Machine-Type Communications (LTE-M), and Narrowband Internet of Things (NB-IoT).
The Background section of this document is provided to place embodiments of the present invention in technological and operational context, to assist those of skill in the art in understanding their scope and utility. Unless explicitly identified as such, no statement herein is admitted to be prior art merely by its inclusion in the Background section.